When "Daddy Long Legs" opens its world premiere engagement at the Laguna Playhouse next week, it will arrive with an impressive array of blood lines.

The author of the original novel was Jean Webster — Mark Twain's great niece. The playwright who brings it to the stage and will direct, John Caird, numbers "Les Miserables" among his musical theater credits.

The composer, Paul Gordon, was Tony-nominated for his score of "Jane Eyre." And the story also inspired a 1955 movie musical with Fred Astaire and Leslie Caron.

That story, set in the early 1900s, focuses on a young orphan girl named Jerusha as she blossoms into a woman. A trustee of the John Grier Orphanage offers Jerusha a proper education — with a few stipulations.

The benefactor's only requirements are that Jerusha never know his identity and that she write him monthly (though he will not respond). She sees him once in the shadows and invents a nickname for her mysterious patron — Daddy Long Legs.

"I decided to make 'Daddy Long Legs' into a musical because I was attracted to it as a novel," Caird explains. "It's a brilliant piece of work.

"This was her first novel, and it's written entirely as letters from the orphan girl Jerusha. You never hear the words of any other character in the novel, so we've gone beyond that and imagined what the man she is writing to is actually like.

"We've given him things to say and things to sing, so the other half of the relationship is filled in," Caird notes.

The playwright-director explains that Jerusha's letters to her patron "paint a moving portrait of her lonely life in the orphanage, the development of her mind and spirit and the growing personal relationship that she develops with her unseen benefactor."

Following four days of previews, Tuesday through Friday of next week, "Daddy Long Legs" will open for the first time anywhere Dec. 4 and play through Dec. 26. Performances will be given Tuesdays through Saturdays at 8 p.m. with weekend matinees at 2 p.m. Special Thursday matinees also are planned for Dec. 2, 16 and 23 at 2 p.m.